Simultaneous Nitrification Simultaneous Nitrification and Denitrification in a and Denitrification in a Sequencing Batch ReactorSequencing Batch Reactor
Will LambertWill Lambert
Robert NwaokoroRobert Nwaokoro
Stephen RussoStephen Russo
SND in SBRSND in SBR
Nitrification/Denitrification Nitrification/Denitrification BasicsBasics
Introduction to SND Experimental Methods Results Conclusions Suggestions/Questions?
Nitrification/Denitrification Nitrification/Denitrification BasicsBasics
Why remove nitrogen?Why remove nitrogen? Limiting nutrient in oceans and estuaries.
Nitrates in drinking water cause Methemoglobinemia
“blue-baby” syndrome.
Nitrification/Denitrification Nitrification/Denitrification BasicsBasics
Denitrification (anaerobic)
Nitrification (aerobic)Nitrosobacters Denitrification (anaerobic)
Nitrification (aerobic)Nitrosomonas
Ammonification
Assimilation
Ammonia
Nitrite
N2 (gas)
Organic Nitrogen
Nitrate
Fixation
Nitrogen Cycle in Waste Treatment
SND in SBRSND in SBR
Nitrification/Denitrification Basics
Introduction to SNDIntroduction to SND Experimental Methods Results Conclusions Suggestions/Questions?
Introduction to SNDIntroduction to SND
What is SND?What is SND? Simultaneous reactions occur of:Simultaneous reactions occur of:
AmmonificationAmmonification NitrificationNitrification DenitrificationDenitrification
Normally occur in different stepsNormally occur in different steps Why use SND? Obstacles to SND Solutions
Introduction to SNDIntroduction to SND
What is SND?
Why use SND?Why use SND? Reduction of:Reduction of:
CostCost EnergyEnergy SludgeSludge
Obstacles to SND Solutions
Introduction to SNDIntroduction to SND
What is SND? Why use SND?
Obstacles to SNDObstacles to SND Nitrification is aerobicNitrification is aerobic Denitrification is anaerobicDenitrification is anaerobic
Solutions
Introduction to SNDIntroduction to SND
What is SND? Why use SND? Obstacles to SND
SolutionsSolutions Achieve aerobic/anaerobic Achieve aerobic/anaerobic
environment:environment: Low DOLow DO
0.5 – 1 mg/L0.5 – 1 mg/L Large flocsLarge flocs BiofilmsBiofilms
SND in SBRSND in SBR
Nitrification/Denitrification Basics Introduction to SND
Experimental MethodsExperimental Methods StatesStates Testing MethodsTesting Methods
Results Conclusions Suggestions/Questions?
Experimental Methods: Experimental Methods: StatesStates
Fill with WasteFill with Waste Run for 18.3 sRun for 18.3 s 140 mL delivered140 mL delivered
Based on 459 mL/min peristaltic pump flow Based on 459 mL/min peristaltic pump flow raterate
Fill with Water Aerate Settle Drain
Experimental Methods: Experimental Methods: StatesStates
Fill with Waste
Fill with WaterFill with Water Run for 350 s AND…Run for 350 s AND… Reactor volume is 4 L over 5 s averageReactor volume is 4 L over 5 s average
Fail safe if pump failed to deliver Fail safe if pump failed to deliver appropriate amount of fluidappropriate amount of fluid
Aerate Settle Drain
Experimental Methods: Experimental Methods: StatesStates
Fill with Waste Fill with Water
AerateAerate Run time variedRun time varied
8, 18, 24 hours8, 18, 24 hours Aeration rate controlled by PID controlAeration rate controlled by PID control
Target DO = 0.5 mg/LTarget DO = 0.5 mg/L Settle Drain
Experimental Methods: Experimental Methods: States: AerateStates: Aerate
Proportional, Integral, and Derivative (PID) Proportional, Integral, and Derivative (PID) ControlControl Equation: Equation:
Trial and error determined Trial and error determined PP, , II, and , and DD values values Effective control was met when DO reached 0.5 mg/LEffective control was met when DO reached 0.5 mg/L
D
D
I
I
P
c tTt
TKtu
1)(
Experimental Methods: Experimental Methods: StatesStates
Fill with Waste Fill with Water Aerate
SettleSettle Run for 1 hourRun for 1 hour
More than enough time for settlingMore than enough time for settling Left unchangedLeft unchanged
Drain
Experimental Methods: Experimental Methods: StatesStates
Fill with Waste Fill with Water Aerate Settle
DrainDrain Run until 1.2 L remained in reactorRun until 1.2 L remained in reactor
SND in SBRSND in SBR
Nitrification/Denitrification Basics Introduction to SND
Experimental MethodsExperimental Methods StatesStates
Testing MethodsTesting Methods Results Conclusions Suggestions/Questions?
Experimental Methods: Testing Experimental Methods: Testing MethodsMethods
Micro-Phenate MethodMicro-Phenate Method Determine ammonia concentration as Determine ammonia concentration as
ammonia/nitrogenammonia/nitrogen Standards consist of:Standards consist of:
Phenol SolutionPhenol Solution Sodium nitroprussideSodium nitroprusside Alkaline citrateAlkaline citrate Sodium hypochloriteSodium hypochlorite Oxidizing SolutionOxidizing Solution
Standards: 0, 0.2, 0.4, 0.6 mg N-NHStandards: 0, 0.2, 0.4, 0.6 mg N-NH44/L /L Spectrophotometer analysis at 640 nmSpectrophotometer analysis at 640 nm
Nitrate-nitrogen standards Sampling
Experimental Methods: Experimental Methods: Testing MethodsTesting Methods
Micro-Phenate Method
Nitrate-nitrogen standardsNitrate-nitrogen standards Cadmium gravimetric methodCadmium gravimetric method
Hach Corporation: Nitriver ® and Nitraver Hach Corporation: Nitriver ® and Nitraver ® reagent packets® reagent packets
Standards: 0, 2, 6, 10 mg N-NOStandards: 0, 2, 6, 10 mg N-NO33/L/L Spectrophotometer analysis at 542nmSpectrophotometer analysis at 542nm
Sampling
Experimental Methods: Experimental Methods: Testing MethodsTesting Methods
Micro-Phenate Method Nitrate-nitrogen standards
SamplingSampling End of aeration stateEnd of aeration state Filtered through Millipore filter Filtered through Millipore filter RefrigeratedRefrigerated Ammonia samplesAmmonia samples
Diluted by 10xDiluted by 10x
SND in SBRSND in SBR
Nitrification/Denitrification Basics Introduction to SND Experimental Methods
ResultsResults Conclusions Suggestions/Questions?
Results: PIDResults: PID
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
4:42:54 PM 5:54:54 PM 7:06:54 PM 8:18:54 PM 9:30:54 PM
Time
DO
(m
g/L
)
DO (mg/L)
Average DO = 0.505 mg/LStandard Deviation = 0.015
Results: Ammonia StandardsResults: Ammonia Standards
-0.1
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
0 200 400 600 800 1000
Wavength (λ)
Ab
sorb
ance
0 mg/L
0.2 mg/L
0.4 mg/L
0.6 mg/L
y = 0.436x - 0.0158
R2 = 0.9737
-0.05
0
0.05
0.1
0.15
0.2
0.25
0.3
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Concentration (mg N-NH3/L)
Abso
rban
ce a
t 640
λ
Results: Nitrate StandardsResults: Nitrate Standards
-0.5
0
0.5
1
1.5
2
2.5
0 200 400 600 800 1000
Wavelength (λ)
Abso
rban
ce 0 mg/L
2 mg/L
6 mg/L
10 mg/L
y = 0.1611x - 0.0451
R2 = 0.9954
-0.2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
0 2 4 6 8 10 12
Concentration (mg N-NO3/L)
Ab
sorb
ance
at
542
λ
Results: SamplesResults: Samples
Aeration Time Aeration Time (hr)(hr)
Absorbance Absorbance (542 nm(542 nm))
Concentration Concentration (mg N-NO(mg N-NO33/L)/L)
2424 0.630.63 4.214.21
1818 0.540.54 3.643.64
88 1.841.84 11.7211.72
Nitrate Concentrations
Aeration TimeAeration Time
(hr)(hr)Absorbance Absorbance
(640 nm)(640 nm)Diluted Diluted
Concentration Concentration (mg (mg
N-NHN-NH33/L)/L)
Actual Actual Concentration Concentration (mg (mg
N-NHN-NH33/L)/L)
2424 1.361.36 3.163.16 31.5731.57
1818 1.221.22 2.832.83 28.3428.34
88 1.051.05 2.442.44 24.4324.43
Ammonia Concentrations
Results: Total Nitrogen Results: Total Nitrogen RemovalRemoval
Aeration Aeration Cycle (hr)Cycle (hr)
Total N Total N Remaining Remaining
(mg/L)(mg/L)
N Removal N Removal (mg/L)(mg/L)
% Removal% Removal
2424 32.3332.33 8.578.57 20.9620.96
1818 35.1935.19 5.715.71 13.9613.96
88 36.1536.15 4.754.75 11.6111.61
SND in SBRSND in SBR
Nitrification/Denitrification Basics Introduction to SND Experimental Methods Results
ConclusionsConclusions Suggestions/Questions?
ConclusionsConclusions
Total nitrogen removal efficiencies appeared Total nitrogen removal efficiencies appeared to make senseto make sense Broken down to nitrate and ammonia, unclear Broken down to nitrate and ammonia, unclear
datadata One long aeration cycle should have been One long aeration cycle should have been
runrun Sampled periodically during that cycleSampled periodically during that cycle
SND is possible at laboratory scale,SND is possible at laboratory scale, Easier at full scaleEasier at full scale
Achieve a more heterogeneous environmentAchieve a more heterogeneous environment
SND in SBRSND in SBR
Nitrification/Denitrification Basics Introduction to SND Experimental Methods Results Conclusions
Suggestions/Questions?Suggestions/Questions?
SuggestionsSuggestions
Questions?Questions?&&